This invention relates to apparatus and methods for creating proofs of documents to be printed on printing presses.
Conventional halftoning is an amplitude modulated process in which continuous shading is simulated by varying the size of equally-spaced printed dots. The resolution at which the dots are placed is called the line screen ruling. The dots are typically oriented at an angle with respect to the print substrate, and this angle is called the screen angle. In grayscale images, the screen angle is typically 45xc2x0, which makes the resulting halftone pattern less noticeable to the human eye. For color images, each of the primary colors (usually cyan, magenta, yellow, and blackxe2x80x94CMYK) are printed at different screen angles in order to minimize color shifts due to misregistration during the printing process. The angles are carefully selected for each color in order to minimize the occurrence of interference patterns called Moire (typical screen angles are C=15xc2x0, M=75xc2x0, Y=0xc2x0, K=45xc2x0).
Proofing is the process of generating a sample print, which represents the output that can be expected from a printing press. Proofing printers (xe2x80x9cproofersxe2x80x9d) are relatively inexpensive printers that strive to accurately represent the press output, including its color and quality. Color management for proofing devices is very important, because such devices generally use different color inks or donors than do the printing presses (proofer CMYKxe2x89xa0press CMYK). And even if a proofing device were to use the same color primaries as a particular press, such a device may not be usable with other presses. This is because not all of them use primary inks with the same hues, with American and European presses exhibiting significant differences in this area. Proofers may also need to match specialty or xe2x80x9cspotxe2x80x9d colors, which are essentially 5th or 6th colors used by the press for colors that the press""s primary colors cannot reproduce well or at all.
In order to produce a color match on the proofer, the image data is typically color corrected before halftone processing. This process results in different data sets being halftone processed for the proofer and the press. Even if the same halftoning technique is used for both machines, the resulting halftone pattern for the two devices will be slightly different in order to make up for the color mismatch.
Some proofing devices focus on matching the color of the press, but appear not to be completely accepted because they use different halftoning techniques than the press. The feeling is that proofs from these devices cannot be used to predict the Moirxc3xa9 that can be expected on the press. Other proofing devices focus on matching the halftoning technique of the press as exactly as possible, but tend not to produce a good color match.
One general aspect of the invention provides for creating half-tone ink-jet proofs on print-enhanced sheets based on an effective image cell pitch of at least about 2400 image cells per inch that substantially matches a cell pitch used to create press plates. This approach has apparently never been tried by the engineers, technicians, and executives employed in the 15 year history of the dedicated digital inkjet contract proofing industry, despite the active participation of around 15 companies, including several large multinational corporations. This manner of thinking appears to result at least in part from a consistent and longstanding focus in the industry on the use of a single ink color set to match different press color sets and spot colors.
In preferred embodiments, print process variables can be adjusted for the ink-jet proofing printer based on received color matching information. These adjustments can define preprint ink mixing ratios that allow at least some image cells to be printed with ink mixtures. Or they can define sub-area printing values that allow at least some dots to be printed with areas of different inks.
Systems according to the invention can exhibit substantial advantages over other existing proofing techniques, including analog proofing techniques, press-specific proofing techniques, and laser deposition proofing techniques. Specifically, while analog proofs can be of high quality, they are cumbersome and expensive to produce. They are also incompatible with the increasingly common all-digital, direct-to-plate approach that the industry is steadily adopting.
Systems according to the invention also exhibit advantages over press-specific proofing techniques because press-specific proofers tend to be expensive and lack versatility. While proofers that match the exact process used on the press can produce high quality proofs, the process they are matching is typically optimized for large-scale printing. Press-specific proofers therefore tend to be more complex and more costly to run on a sheet-by-sheet basis. They also cannot generally be used to produce accurate proofs for presses that use other processes. And xe2x80x9cdual-usexe2x80x9d presses that include proofing capabilities generally cannot produce proofs without tying up their expensive high volume press capabilities, and cannot produce them at all during their long, high-volume runs.
Systems according to the invention exhibit advantages over laser deposition techniques because such techniques employ expensive proofers and rely on donor sheets that are bulky, expensive, and can be cumbersome to load, ship, and store. In addition, only a relatively small number of colors of donor sheets are currently available, even though this technique has been around for some time. And while print shops could produce their own sheets for particular requirements, this adds further complexity and expense to an already relatively cumbersome and expensive technique.
Generally, this aspect of the invention provides for a method of printing an inkjet proof of a document to be printed with a half-tone reference printer that uses one of four or more different inks with each of a number of different plates produced by a setter based an effective horizontal image cell pitch of at least about 2400 image cells per inch and an effective vertical image cell pitch of at least about 2400 image cells per inch. The method includes receiving print data that describes half-tone dots having a predetermined perimeter using image cells at substantially the same horizontal image cell pitch and substantially the same vertical image cell pitch that is used by the setter to create the plates for the reference printer for the four or more colors. A proofing sheet is received including a first rectangular deposited ink drop printable face having a periphery defined by an ordered series of first, second, third, and fourth edges of the proofing sheet, and including a second face opposite the first face and also having a periphery being defined by the first, second, third, and fourth edges of the imposition proofing print sheet, with at least the first face having properties resulting from a deposited ink drop print-enhancing treatment. A half-tone proof is made for the four or more colors with an inkjet proofer on at least the first face of the proofing sheet at substantially the same horizontal cell pitch as the effective horizontal cell pitch of the data received in the step of receiving and at substantially the same vertical cell pitch as the effective vertical cell pitch of the data received in the step of receiving.
In preferred embodiments, color matching information can be received for the ink set to be used by the reference printer to print the document, print process variables can be adjusted for the inkjet proofing printer based on the color matching information received in the step of receiving, and printing can occur according to these process variables. The step of adjusting can define preprint ink mixing ratios, with the step of printing printing at least some of the image cells with ink mixtures. The step of adjusting can define sub-area printing values, with the step of printing printing at least some of the dots with a plurality of areas of different inks. The step of adjusting can define sub-area printing values, with the step of printing printing at least some of the dots with at least one overlapping ink area. The step of adjusting can define sub-area printing values, and with the step of printing printing at least some inked dots with at least one blank area within their perimeters. The step of printing can employ the same electronic print representation used by the setter. The setter can be a direct-to-plate plate setter that produces the plates directly, with the electronic print representation being an electronic print representation readable by the plate setter. The setter can be a reduced format film setter that produces scaled films at a scaled resolution that when enlarged to produce the plates produces plates that are based on the effective resolution, with the electronic print representation being an electronic print representation readable by the film setter. The step of printing can print one image cell for each of substantially all of the image cells in the data received in the step of receiving on a print substrate for at least one of the plates. The second face can have properties resulting from the deposited ink drop print-enhancing treatment. The step of proofing can employ a proofing sheet that is a B-size or larger sheet. The step of proofing can employ a proofing sheet that is a 4-up or larger sheet. The step of making a proof can employ a continuous inkjet printing technique or a drop-on-demand printing technique. The step of making a proof can employ dye-based inks. The step of proofing can employ software, ink, and media having tolerances that produce an effective color range of 4xcex94e in CIE color space. The step of receiving a proofing sheet can receive a proofing sheet with the second face also having properties resulting from a deposited ink drop print-enhancing treatment, with the step of making a half-tone proof further making a half-tone proof on the second face of the proofing sheet at substantially the same horizontal cell pitch as the effective horizontal cell pitch of the data received in the step of receiving and at substantially the same vertical cell pitch as the effective vertical cell pitch of the data received in the step of receiving.
In another general aspect, the invention features an inkjet proofer for printing an inkjet proof of a document to be printed with a half-tone reference printer that uses one of four or more different inks with each of a number of different plates produced by a setter based an effective horizontal image cell pitch of at least about 2400 image cells per inch and an effective vertical image cell pitch of at least about 2400 image cells per inch. The proofer includes storage for print data that describes half-tone dots having a predetermined perimeter using image cells at substantially the same horizontal image cell pitch and substantially the same vertical image cell pitch that is used by the setter to create the plates for the reference printer for the four or more colors. A feed mechanism is provided for receiving a proofing sheet including a first rectangular deposited ink drop printable face having a periphery defined by an ordered series of first, second, third, and fourth edges of the proofing sheet, and including a second face opposite the first face and also having a periphery being defined by the first, second, third, and fourth edges of the imposition proofing print sheet, with at least the first face having properties resulting from a deposited ink drop print-enhancing treatment. The proofer also includes logic responsive to the storage for generating a half-tone proof for the four or more colors with an inkjet proofer on at least the first face of the proofing sheet received by the feed mechanism at substantially the same horizontal cell pitch as the effective horizontal cell pitch of the data received in the step of receiving and at substantially the same vertical cell pitch as the effective vertical cell pitch of the data received in the step of receiving.
In a further general aspect, the invention features an inkjet proofer for printing an inkjet proof of a document to be printed with a half-tone reference printer that uses one of four or more different inks with each of a number of different plates produced by a setter based an effective horizontal image cell pitch of at least about 2400 image cells per inch and an effective vertical image cell pitch of at least about 2400 image cells per inch. The proofer includes means for storing print data that describes half-tone dots having a predetermined perimeter using image cells at substantially the same horizontal image cell pitch and substantially the same vertical image cell pitch that is used by the setter to create the plates for the reference printer for the four or more colors.
Also provided are means for receiving a proofing sheet including a first rectangular deposited ink drop printable face having a periphery defined by an ordered series of first, second, third, and fourth edges of the proofing sheet, and including a second face opposite the first face and also having a periphery being defined by the first, second, third, and fourth edges of the imposition proofing print sheet, with at least the first face having properties resulting from a deposited ink drop print-enhancing treatment. The proofer further includes means responsive to the means for storing for generating a half-tone proof for the four or more colors with an inkjet proofer on at least the first face of the proofing sheet received by the means for receiving at substantially the same horizontal cell pitch as the effective horizontal cell pitch of the data received in the step of receiving and at substantially the same vertical cell pitch as the effective vertical cell pitch of the data received in the step of receiving.
In another general aspect, the invention features a proof generation method for proof printers that includes the step of receiving print data to be printed on a target halftone printing press to which a first halftoning technique has been applied, wherein the first halftoning technique is at least comparable to a target halftoning technique used by the target halftone printing press, applying a second halftoning technique to the print data, wherein the first and second halftoning techniques are different, and providing the data to a proofing printer different from the target halftone printing press.
In preferred embodiments, the step of applying a first halftoning technique can apply a half-toning technique that employs constantly spaced dots of variable sizes with the step of applying a second halftoning technique applying a stochastic halftoning technique to the constantly spaced dots of variable sizes. The print data can be color print data including a plurality of color-separated data subsets, with the step of applying a first halftoning technique and the step of applying a second halftoning technique being applied to the data subsets. The step of applying a first halftoning technique can employ dots from a first set of primary colors, with the step of applying a second halftoning technique adding at least a second of the primary colors to a portion of one or more of the dots assigned to a first of the primary colors based on the first halftoning technique. The step of applying a first halftoning technique can employ dots from a first set of primary colors with the step of applying a second halftoning technique adding at least a first additional color to a portion of one or more of the dots assigned to a first of the primary colors based on the first halftoning technique. The step of applying a first halftoning technique can employ dots from a first set of primary colors, with the step of applying a second halftoning technique adding at least a first additional color to a portion of one or more of the dots assigned to a first of the primary colors based on the first halftoning technique. The method can further include the steps of receiving a target printing press selection command and selecting parameters for the second halftoning technique based on the target printing press selection command. The step of applying a first halftoning technique and the step of applying a second halftoning technique can be applied as part of a single simultaneous process. The method can further include the step of printing the data with an ink-jet proofing printer different from the target halftone printing press. The step of applying a first halftoning technique can employ dots, with the step of applying a second halftoning technique resulting in lightening colorant values for at least some areas of at least some of the dots from the first halftoning technique. The step of applying a first halftoning technique can employ dots, with the step of applying a second halftoning technique causing the complete lightening of colorant values for at least some areas of at least some of the dots from the first halftoning technique. The step of applying a first halftoning technique can employ dots, with the step of applying a second halftoning technique causing the substitution of colorant from at least some areas of at least some of the dots from the first halftoning technique with a different colorant. The step of applying a first halftoning technique can employ dots, with the step of applying a second halftoning technique causing the overlaying of a different colorant on at least some areas of at least some of the dots from the first halftoning technique. The step of applying a first halftoning technique can employ dots, with the step of applying a second halftoning technique causing the creation of a plurality of areas of a same color within at least some of the dots from the first halftoning technique. The step of applying a first halftoning technique can employ dots, with the step of applying a second halftoning technique causing the creation of a plurality of areas as individual pixels. The step of applying a first halftoning technique can employ dots, with the step of applying being applied to the dots corresponding to a spot color defined by the print data to match the spot color. The print data can be based on a first set of complementary subtractive colorants, with the proofing printer being an ink set based on a second set of complementary subtractive colorants that includes the same qualitative colors as the first set, but wherein at least one of the colorants in the first set exhibits some degree of mismatch with respect to a corresponding one of the colorants in the second set. The first and second sets can both be based on cyan, magenta, and yellow. The second set can be based on cyan and magenta that both have a hue chosen such that they will substantially always require yellow contamination. The proofing printer can be an ink-jet based proofing printer. The print data can be provided to the target halftone printing press. Changes can be made in the print data based on examination of a proof from the proofing printer before printing it on the target press.
In a further general aspect, the invention features a proof generation apparatus for proof printers that includes a print data input responsive to a first halftone processor employing a first halftone technique, wherein the first halftoning technique is at least comparable to a target halftoning technique used by the target halftone printing press. A second halftone processor employs a second halftone technique, with the first and second halftoning techniques being different. The apparatus further includes a processed print data output.
In another general aspect, the invention features a proof generation apparatus for proof printers that includes means for receiving print data to be printed on a target halftone printing press from means for applying a first halftoning technique to the print data, wherein the first halftoning technique is at least comparable to a target halftoning technique used by the target halftone printing press, means for applying a second halftoning technique to the print data, wherein the first and second halftoning techniques are different, and means for providing the data to a proofing printer different from the target halftone printing press.
In a further general aspect, the invention features a proof generation method for ink jet proof printers that includes receiving print data to be printed on a target halftone printing press to which a first halftoning technique has been applied to obtain screen image data representing a plurality of screen dots, which yield a shaded visual representation of the image when printed on a printing press, creating one or more lightened areas where direct deposition of colorant is to be lightened within at least some of the screen dots to be printed but where indirect deposition colorant from overlapping areas is to remain, wherein the method is optimized to accurately reproduce the shaded visual image that would be printed on the printing press, and providing the data to an inkjet proofing printer different from the target halftone printing press and capable of printing the overlapping areas.
In preferred embodiments, the method can include a step of receiving an adjustment signal and a step of adjusting parameters of the step of lightening in response to the step of receiving a user adjustment signal. The method can include the step of printing the data with overlapping dots for the overlapping raster pattern using an ink-jet proofing printer different from the target halftone printing press. The step of creating can create the lightened areas as individual pixels. The steps of creating and providing can be adapted to produce complete overlap of the lightened areas.
In another general aspect, the invention features proof generation apparatus for ink jet proof printers that includes a print data input responsive to a series of screen dots from first halftone processor employing a first halftoning technique, wherein the plurality of dots yield a shaded visual representation of the image when printed on a printing press, lightening logic for creating one or more lightened areas where direct deposition of colorant is to be lightened within at least some of the screen dots to be printed but where indirect deposition colorant from overlapping areas is to remain, and wherein the apparatus is optimized to accurately reproduce a shaded visual image that would be printed on the printing press, and a processed print data output for providing the data to an ink-jet proofing printer different from the target halftone printing press and capable of printing the overlapping areas.
In a further general aspect, the invention features proof generation apparatus for ink jet proof printers that includes means for receiving print data to be printed on a target halftone printing press to which a first halftoning technique has been applied to obtain screen image data representing a plurality of screen dots, which yield a shaded visual representation of the image when printed on a printing press, means for creating one or more lightened areas where direct deposition of colorant is to be lightened within at least some of the screen dots to be printed but where indirect deposition colorant from overlapping areas is to remain, wherein the apparatus is optimized to accurately reproduce the shaded visual image that would be printed on the printing press, and means for providing the data to an ink-jet proofing printer different from the target halftone printing press and capable of printing the overlapping areas.
In another general aspect, the invention features a proof generation method for ink jet proof printers that includes receiving print data to be printed on a target halftone printing press to which a first halftoning technique has been applied, wherein the first halftoning technique is at least comparable to a target halftoning technique used by the target halftone printing press, lightening at least one portion of each of at least some of the screen dots, adding at least one region of a second color in some of the screen dots, and providing the screen image data to a proofing printer different from the target halftone printing press.
In preferred embodiments, the step of applying a first halftoning technique, the step of lightening, and the step of adding can be applied as part of a single simultaneous process before the step of providing. The method can further include the step of printing the data with an ink-jet proofing printer different from the target halftone printing press. The step of applying a first halftoning technique can employ dots, with the step of applying a second halftoning technique causing the complete lightening of colorant values for at least some areas of at least some of the dots from the first halftoning technique. The step of applying a first halftoning technique can employ dots, with the step of applying a second halftoning technique causing the overlaying of colorant from at least some areas of at least some of the dots from the first halftoning technique with a different colorant. The step of applying a first halftoning technique can employ dots, with the step of applying a second halftoning technique causing the creation of a plurality of areas of a same color within at least some of the dots from the first halftoning technique.
In a further general aspect, the invention features proof generation apparatus for proof printers that includes a print data input responsive to a first halftone processor employing a first halftone technique, wherein the first halftoning technique is at least comparable to a target halftoning technique used by the target halftone printing press, lightening logic for lightening at least one portion of each of at least some of the screen dots, an adder for adding at least one region of a second color in some of the screen dots, and a processed print data output.
In another general aspect, the invention features proof generation apparatus for proof printers that includes means for receiving print data to be printed on a target halftone printing press to which a first halftoning technique has been applied, wherein the first halftoning technique is at least comparable to a target halftoning technique used by the target halftone printing press, means for lightening at least one portion of each of at least some of the screen dots, means for adding at least one region of a second color in some of the screen dots, and means for providing the screen image data to a proofing printer different from the target halftone printing press.
In a further general aspect, the invention features a proof generation method for proof printers that includes receiving print data to be printed on a target halftone printing press to which a first halftoning technique has been applied, wherein the first halftoning technique produces a plurality of dots and is at least comparable to a target halftoning technique used by the target halftone printing press, altering at least a plurality of areas distributed within at least some of the dots with substantially the same color alteration, and providing the data to a proofing printer different from the target halftone printing press.
In preferred embodiments, the step of altering can alter the areas to include a same color that is different from the color of the dot. The step of altering can operate according to a set of primary colors that is adjusted to increase the altering of at least a first color by a second color in favor of a decrease in the altering of the first color by a third color that is darker than the second color. The step of altering can alter the areas to lighten the color of the dot. The step of altering can alter dots corresponding to a spot color defined by the print data to match the spot color. The data can be printed with an ink-jet proofing printer different from the target halftone printing press. The print data can be based on a first set of complementary subtractive colorants, with the proofing printer having an ink set based on a second set of complementary subtractive colorants that includes the same qualitative colors as the first set, but wherein at least one of the colorants in the first set exhibits some degree of mismatch with respect to a corresponding one of the colorants in the second set. The first and second sets can both be based on cyan, magenta, and yellow. The second set can be based on cyan and magenta that both have a hue chosen such that they will substantially always require yellow contamination. The proofing printer can be an ink-jet based proofing printer. The print data can be provided to the target halftone printing press. The method can further include the step of making changes in the print data based on examination of a proof from the proofing printer before printing it on the target press.
In another general aspect, the invention features a proof generation apparatus for proof printers that includes a print data input responsive to a first halftone processor employing a first halftone technique, wherein the first halftoning technique is at least comparable to a target halftoning technique used by the target halftone printing press, altering logic for altering at least a plurality of areas distributed within at least some of the dots with substantially the same color alteration, and a processed print data output.
In a further general aspect, the invention features a proof generation apparatus for proof printers that includes means for receiving print data to be printed on a target halftone printing press to which a first halftoning technique has been applied, wherein the first halftoning technique produces a plurality of dots and is at least comparable to a target halftoning technique used by the target halftone printing press, means for altering at least a plurality of areas distributed within at least some of the dots with substantially the same color alteration, and means for providing the data to a proofing printer different from the target halftone printing press.
In a further general aspect, the invention features a proof generation method for proof printers that includes receiving halftoned print data to be printed on a target halftone printing press to which a first halftoning technique has been applied, wherein the first halftoning technique is at least comparable to a target halftoning technique used by the target halftone printing press, accessing color recipes that specify color values for the target halftone printing press in terms of color values for a proofing printer in response to the halftoned print data, producing proof print data based on the color values accessed in the step of accessing, and providing the proof printing data to the proofing printer different from the target halftone printing press.
In preferred embodiments, the step of producing proof printing data can employ a stochastic halftoning method. The stochastic halftoning method can employ stochastic thresholding arrays. The step of retrieving can retrieve the same recipe for differently sized halftone dot data values in the halftoned data. The step of retrieving can include receiving different values for both primaries and overprints.
In another general aspect, the invention features proofing apparatus that includes color recipe storage for storing color recipes that specify color values for the target halftone printing press in terms of color values for a proofing printer in response to halftoned print data to be printed on a target halftone printing press to which a first halftoning technique has been applied, wherein the first halftoning technique is at least comparable to a target halftoning technique used by the target halftone printing press, logic for producing proof printing data responsive to the color recipe storage, and a proofing print engine different from the target halftone printing press and responsive to the logic for producing proof printing data.
In preferred embodiments, the logic for producing proof printing data can employ a stochastic halftoning method. The stochastic halftoning method can employ stochastic thresholding arrays. The storage can store the same recipe for differently sized halftone dot data values in the halftoned data. The step of storing can store different values for both primaries and overprints.
In a further general aspect, the invention features proofing apparatus that includes means for receiving halftoned print data to be printed on a target halftone printing press to which a first halftoning technique has been applied, wherein the first halftoning technique is at least comparable to a target halftoning technique used by the target halftone printing press, means for accessing color recipes that specify color values for the target halftone printing press in terms of color values for a proofing printer in response to the halftoned print data, means for producing proof print data based on the color values accessed in the step of accessing, and means for providing the proof printing data to the proofing printer different from the target halftone printing press.
In another general aspect, the invention features an inkjet printing apparatus that includes a body defining a chamber, a plunger sized to move within the chamber, an actuator operatively connected to the plunger, an outlet defined in the chamber and operatively connected to an inkjet printing nozzle, a plurality of inlets defined in the chamber and each being operatively connected to one of a plurality of ink supply reservoirs, and a linear controller having a control input provided to the linear actuator.
In preferred embodiments, the actuator can be a stepper motor, with the linear controller being operative to supply a signal that includes a number of step pulses to windings of the stepper motor. A gasket can be proximate the head of the piston. A mixer can be operative to mix contents of the mixing chamber. The printer can include a plurality of chambers each responsive to a plurality of ink supply reservoirs. The printer can include a mixing chamber for each of the following colors: cyan, magenta, yellow, and black. The printer further can include a mixing chamber for at least one further color. The printer can include a dilution fluid chamber that has an output orifice, with the mixing chamber also being operatively connected to the dilution fluid chamber. The linear controller can be responsive to an ink recipe database.
In a further general aspect, the invention features an inkjet printing method that includes storing a plurality of inks, receiving an ink recipe defining at least one recipe color based on a plurality of inks, providing a succession of commands to a linear actuator, the commands corresponding to ink recipe amounts for the plurality of inks, moving the recipe amounts of the stored inks into a chamber by the linear actuator, and depositing the resulting recipe color using an inkjet printing method.
In preferred embodiments, the inks can be actively mixed in the chamber. The steps of receiving, storing, providing, drawing, and depositing can operate on each of the following colors: cyan, magenta, yellow, and black. The steps of receiving, storing, providing, drawing, and depositing can also operate on a dilution fluid.
In another general aspect, the invention features an inkjet printing apparatus that includes means for storing a plurality of inks, linear actuation means for moving the inks stored in the means for storing into a mixing chamber, means for providing a succession of commands to the linear actuator, the commands corresponding to ink recipe amounts for the plurality of inks stored in the means for storing, and means responsive to the mixing chamber for depositing the resulting recipe color using an inkjet printing method.
In a further general aspect, the invention features a method of printing an inkjet proof of a document to be printed with a half-tone reference printer that uses one of three or more different inks with each of a number of different plates produced by a setter based an effective horizontal image cell pitch and an effective vertical image cell pitch. The method includes receiving print data that describes half-tone dots having a predetermined perimeter using image cells at substantially the same horizontal image cell pitch and substantially the same vertical image cell pitch that is used by the setter to create the plates for the reference printer for the four or more colors, receiving predetermined amounts of a plurality of inks from a plurality of ink reservoirs to define a first mixed ink-jet ink of a predetermined color, receiving predetermined amounts of a plurality of inks from a plurality of ink reservoirs to define a second mixed ink-jet ink of a predetermined color, receiving predetermined amounts of a plurality of inks from a plurality of ink reservoirs to define a third mixed ink-jet ink of a predetermined color, receiving a proofing sheet including a first rectangular deposited ink drop printable face having a periphery defined by an ordered series of first, second, third, and fourth edges of the proofing sheet, and including a second rectangular face opposite the first face and also having a periphery being defined by the first, second, third, and fourth edges of the imposition proofing print sheet, with at least the first face having properties resulting from a deposited ink drop print-enhancing treatment, and generating a halftone proof by depositing the first, second, and third mixed inks on at least the first face of the proofing sheet at substantially the same horizontal cell pitch as the effective horizontal cell pitch of the data received in the step of receiving and at substantially the same vertical cell pitch as the effective vertical cell pitch of the data received in the step of receiving.
In preferred embodiments, the steps of mixing can be specified to match inks to be used on a reference printer. The method can further include the step of receiving predetermined amounts of a plurality of inks from a plurality of ink reservoirs to define a fourth mixed inkjet ink of a predetermined color, with the step of generating generating a halftone proof by further depositing the fourth mixed ink. The first, second, and third inks can be cyan, magenta, and yellow inks, respectively.
In another general aspect, the invention features an inkjet proofer for printing an inkjet proof of a document to be printed with a half-tone reference printer that uses one of four or more different inks with each of a number of different plates produced by a setter based an effective horizontal image cell pitch and an effective vertical image cell pitch. The proofer includes a first reservoir for a first ink of a predetermined color, a second reservoir for a second ink of a predetermined color, a third reservoir for a third ink of a predetermined color, a mixing chamber responsive to the first, second, and third reservoirs, and logic for generating a halftone proof by depositing the first, second, third, and fourth mixed inks on at least the first face of a proofing sheet at substantially the same horizontal cell pitch as the effective horizontal cell pitch of the data for the reference printer and at substantially the same vertical cell pitch as the effective vertical cell pitch of the data for the reference printer.
In preferred embodiments, the first, second, and third colors are: cyan, magenta, and yellow. The proofer can include a dilution fluid chamber having an output orifice, with the mixing chamber also being responsive to the dilution fluid chamber.
In a further general aspect, the invention features an inkjet proofer for printing an inkjet proof of a document to be printed with a half-tone reference printer that uses one of four or more different inks with each of a number of different plates produced by a setter based an effective horizontal image cell pitch and an effective vertical image cell pitch. The proofer includes means for receiving print data that describes half-tone dots having a predetermined perimeter using image cells at substantially the same horizontal image cell pitch and substantially the same vertical image cell pitch that is used by the setter to create the plates for the reference printer for the four or more colors, means for receiving predetermined amounts of a plurality of inks from a plurality of ink reservoirs to define a first mixed ink-jet ink of a predetermined color, means for receiving predetermined amounts of a plurality of inks from a plurality of ink reservoirs to define a second mixed ink-jet ink of a predetermined color, means for receiving predetermined amounts of a plurality of inks from a plurality of ink reservoirs to define a third mixed ink-jet ink of a predetermined color, means for receiving a proofing sheet including a first rectangular deposited ink drop printable face having a periphery defined by an ordered series of first, second, third, and fourth edges of the proofing sheet, and including a second rectangular face opposite the first face and also having a periphery being defined by the first, second, third, and fourth edges of the imposition proofing print sheet, with at least the first face having properties resulting from a deposited ink drop print-enhancing treatment, and means for generating a halftone proof by depositing the first, second, and third mixed inks on at least the first face of the proofing sheet at substantially the same horizontal cell pitch as the effective horizontal cell pitch of the data received by the means for receiving and at substantially the same vertical cell pitch as the effective vertical cell pitch of the data received in the step of receiving.
Systems and methods according to the invention can permit substantially better simulation by a proofer of the output of a target press. By superimposing two halftoning techniques together or by mixing inks, such systems and methods can yield a proof that represents the halftone pattern as well as the color of the press, and this proof should allow Moirxc3xa9 patterns to be predicted more accurately. Predicting Moirxc3xa9 patterns can allow a user to correct them before undertaking the potentially expensive and time consuming task of running the print job on the press.
Systems and methods according to the invention can provide these advantages with minimal impact on the printed halftone dots. By spreading dots around and using a printer that exhibits some overlap, the visual impact of the second halftoning technique can be minimized. As a result, the proof can also more closely predict press output when inspected under magnification. And by providing for recipe lookup based on combined screened bitmap data, proofs can be obtained in a highly efficient manner.